Writing instrument



FIG. 1 is a perspective view showing our new design;

FIG. 2 is a front elevational view of the writing instrument of FIG. 1;

FIG. 3 is a left side elevational view of the writing instrument of FIG. 1, the left side elevational view being a mirror image thereof;

FIG. 4 is a rear elevational view of the writing instrument of FIG. 1; and,

FIG. 5 is a bottom plan view of the writing instrument of FIG. 1.

The dashed lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a “writing instrument,” as shown and described. 